The present invention generally relates to a variable magnification copying machine capable of calculating a conversion magnification from sizes of an original sheet and a transfer paper sheet, and more particularly, to a variable magnification copying machine capable of copying onto transfer paper sheets, with margins being formed therein.
In recent years, copying machines with the function of the variable magnification have been produced due to a tendency toward multifunction thereof, and furthermore, it has been attempted to simplify a copying operation with variable magnifications.
As one of the variable magnification copying machines, for example, Japanese Patent Laid-Open Application Tokkaisho No. 54-92318 discloses the provision of a detecting unit for an original sheet size at the lower portion of an original sheet platform and a unit for detecting or inputting a transfer paper sheet size to be set, and the conversion magnification is calculated by the sizes of the original sheet and the transfer paper sheet to be detected or inputted, to control rotating speeds of an optical system and a photoconductive drum in accordance with the calculation result.
In making copies with magnification converted from the original sheet of irregular size to the transfer paper sheet of regular size by means of said conventional variable magnification copying machine, there has been such a possibility that an image from the original sheet at a basic position on its platform may be copied to one side on the transfer paper sheet. It is hard to read the contents of copies with such images to be put to one side as aforementioned, and the images have a possibility to be hidden under a binder, when the copies are to be bound in a file.
With the intention of arranging the image around the central portion of the transfer paper sheet to remove the inconvenience as described above or arranging it at the desired position according to other purposes, it has been necessary to find out the most suitable position by repeated copies at each time after gradual shifting of the original sheet on its platform.
In the practice as described above, however, since various kinds of erroneous copies occur, with complicated and time consuming copying operations being additionally required, there has been such an inconvenience that the working efficiency of the copying machine is considerably lowered.
Furthermore, in the case of making copies with magnification converted from the original sheet of regular form to the transfer paper sheet of regular form, the margins cannot be formed on the transfer paper sheet due to the constant ratio of a long side length to a short side length in each paper size. Such being the case, for example, for filing the copies after the magnification to transfer paper sheets of B4 size from original sheets of A4 size having images covering the surface, the images are copied on the whole surface of transfer paper sheets of B4 size, and as a result, such disadvantages have occurred as parts of the images being hidden under a binder or being removed when perforated.